I recently sold my 1854 Rudall Rose, & Carte rosewood flute and have been shopping around for a replacement. I loved the Rudall, and would never have let it go if it were tuned to 440. I was on the mainland for work this last week and had the chance to try out a Muramatsu GX and a Sankyo 301. I found that while the Muramatsu was lovely in the middle and upper registers, I had a hard time sounding the low register with it. I was able to get a nice lower register with the Sankyo, but I had a hard time getting a tone I was happy with in the upper registers. TBH, I would have been sold on the Muramatsu if I could have gotten as nice a tone on the low end as the high. The middle and upper registers were just stellar.
That led me back to my hotel room where I started doing a bit more homework on other flutes I might like to try while I had the opportunity. I noticed on the Di Zhao website that all of their flutes are tuned to 442, which won't work for me. That led me a bit further down the rabbit hole, and I couldn't find any other manufacturer who openly said what the flutes were tuned to. Ultimately, I'll probably buy something used, as whatever I buy won't stay in new condition, and I'm happy to let someone else absorb the depreciation. The question is, where can I find tuning information? I'm just not willing to spend money on something that's not tuned to 440.